Network service providers enable data communication services using networks interconnected via switches and routing devices including provider edge (PE) routers and customer edge (CE) routers. Customer edge routers communicatively couple customer equipment (e.g., computers and other processor systems, local routers, and local switches) to wide are networks (WANs) via PE routers. Provider edge routers are communicatively coupled to other PE routers across a WAN to enable communicating information between local CE routers and remote CE routers. To deliver data, each PE router is provided with routes that can be used to forward data packets based on destination addresses stored therein. A PE router stores each route in a routing table, and retrieves that route from the routing table each time the PE router receives a data packet having a destination address matching the destination address associated with that route.
As service providers expand their networks, additional routes are brought on line to enable data communications with the new portions of the network. Each time an additional route is created, PE routers to which that route is relevant must store the route in their routing tables. As the quantity of routes increase, so do the requirements for memory capacity to store those routes. Memory capacity for routing tables is typically increased in a network by adding additional routers. In this manner, each time a new router is added, its memory capacity is also added to the network to store additionally created routes. Thus, instead of having to store a single relatively long listing of routes in one router, installing another router enables storing a first portion of the route listing in a first router and storing a second portion of the route listing in the other router. The first router then handles data packets for which it has relevant routes in its stored portion of the route listing, and the other router handles data packets for which it has relevant routes in its stored portion of the route listing.